1. Field of the Invention
The present invention relates generally to distance measuring devices. More specifically, the invention is a ruler having one or multiple scales for directly reading horizontal distances or elevations on topographical maps in yards and miles.
2. Description of the Related Art
A wide variety of measuring devices have been devised for measuring distances according to specific scale magnitudes and units depending on the area of application. For the average nature enthusiasts, however, a measuring device which measures horizontal distances or elevations for topographical maps as herein described is wanting. Invariably, avid hikers find it necessary to determine travel progress whether in mountains, rain forests, wilderness, etc., by estimating distances of completed travel or remaining distance of travel via natural landmarks, solar activity, including more advanced or technical means such as the use of hand-held measuring devices. For example, costly devices such as global positioning systems and more conventional devices such as magnetic compasses, etc. have been used by hikers to aide in determining there directional bearings in various locations, but the more critical data which describes changes in elevations or physical data regarding the terrain, etc. is not provided by these devices. However, the measuring device according to the instant invention allows one to draw inference from such data wherein one measures topographical maps to ascertain the rigors of the terrain and whether one has sufficient energy or stamina to continue a course of direction or alter the course to reach a particular destination.
While an experienced hiker could probably survive without devices such as compasses, rulers or natural landmarks, a measuring device for measuring distances on topographical maps as herein described is quite useful in aiding a hiker or ground rescue team for that matter in determining local topographical data to cover areas wherein persons may be found thereby conserving energy to meet or alter destination plans according to the rigors of a certain environmental domain of search. Most of the conventional devices used by hikers as described hereinbelow are lacking in this critical area.
For example, U.S. Pat. No. 291,429 issued to Tuttle discloses a conventional graduated scale which measures distance in inches and centimeters. If a drawing is on a scale of one hundred feet to the inch, a fiftieth scale is used. In the case the number of feet is even--for instance, two hundred and forty--ten inches are measured off from the zero toward the left of the measuring device, and forty feet (equal to twenty on the fiftieths scale) are measured off on the same. There is no explicit teaching wherein topographical measurement are made in corresponding yard and mile measurements as herein described.
U.S. Pat. No. 1,497,492 issue to Engel discloses a multiple scale instrument for making measurements in feet and inches in particular. Although beneficial in some applications wherein logarithmic scales are needed, the multiple scale device taught by Engel is quite complex to use. The device according to the instant invention is quite simple to use as measurements from topographical maps are readily obtained.
U.S. Pat. No. 4,217,696 issued to Schindler discloses a time-distance device for measuring linear or curvilinear map distance and determining the rate or time of travel represented by such distance. The device includes an elongated, hollow body having a slot extending along a portion of its length, an indicator shiftable along the slot, and a traction element rotatably mounted at one end of the body. The device according to the instant invention is substantially rectangular and does require a rotatable cylindrical member. The Russian Patent No. 2216265 issued to Balley also discloses a time distance map reading aide having a scale calibrated in a personal mobility parameter. The device includes four scales indicating walking speeds 1/2, 11/2, 21/2 and 31/2 miles per hour.
U.S. Pat. Nos. issued to Samuels (4,484,395), Tzen (4,641,436) and Pan (4,734,993) disclose straight edge measuring devices which are capable of measuring both horizontal and perpendicular distances. The latter U.S. Patents issued to both Tzen and Pan provide such measurements simultaneously via L-shaped measuring scales.
U.S. Pat. No. 5,479,719 issued to Liu discloses a triangular shaped multi-scale rolling ruler. The ruler is made roll along a planar surface and to rotate to arrange an alternate scale in place for appropriate measurements. The primary purpose of this particular design is to improve the drawing of parallel lines of different scales by preventing ink from contaminating a work sheet. This device is completely different than that of the instant invention in that there are no requirements for the rolling features to obviate ink contamination on a work sheet as recited above. Other Patents which are generally relevant to the instant invention are those issued to Watts (U.S. Pat. No. 5,664,334) and Socina (CH 273116) which disclose measuring devices which determine the angle of inclination of a portion of terrain from a topographical map for example.
None of the above inventions and patents, taken either singularly or in combination, is seen to describe the instant invention as claimed. Thus a measuring device for topographical maps solving the aforementioned problems is desired.